Subsea fluid delivery system and method

ABSTRACT

A system for delivering fluids to a subsea device comprises a first fluid pressurizer for pressurizing fluid at a first pressure in communication with a fluid pressure intensifier located subsea that is capable of increasing the fluid pressure of the fluid. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope of meaning of the claims.

PRIORITY INFORMATION

This application claims the benefit of U.S. Provisional Application No.60/616,240, filed on Oct. 6, 2004.

FIELD OF THE INVENTION

The inventions relate to a system and method for delivering fluid underpressure for use subsea.

BACKGROUND OF THE INVENTION

Subsea devices often require fluids, e.g. hydraulic fluids or chemicalsfor injection and the like. These fluids are typically delivered to thedevice under pressure. As subsea devices are deployed deeper and deeper,the pressures required have increased.

Existing installation workover control systems are limited in theprojects on which they can be used, in part due to the pressure ratingsof umbilicals used to provide fluids under pressure from a source offluids, e.g. a surface vessel, to devices subsea that need that fluid.Deepwater trees, for example, will or currently need fluid pressures inthe ranges that exceed 10,000 psi.

Additionally, umbilicals from the surface currently need to contain aplurality of fluid conduits which increases cost and complexity. Thegreater the number of required conduits, the greater the cost associatedwith the umbilical.

BRIEF DESCRIPTION OF THE DRAWINGS

The various drawings supplied herein are representative of one or moreembodiments of the present inventions.

FIG. 1 is a planar view in of an exemplary system;

FIG. 2 is a cross-sectional view of an exemplary conduit;

FIG. 3 is a planar view of a second exemplary system; and

FIG. 4 is a flowchart of an exemplary method.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTIONS

Referring now to FIG. 1, system 1 is adapted to provide fluid underpressure to a subsea device, e.g. a device adapted for use in aninstallation workover control system. In a preferred embodiment, system1 comprises fluid source 10 located distally from seabed 100 and adaptedto provide fluid 5 suitable for use with the subsea device, e.g. toprovide a subsea installation workover function; fluid pressurizer 20 influid communication with fluid source 10, fluid pressurizer 20 adaptedto pressurize fluid 5 to a first pressure; fluid pressure intensifier 30adapted to be located subsea, fluid pressure intensifier 30 furtheradapted to receive fluid 5 at a first fluid pressure and output fluid 5at a fluid pressure higher than the first fluid pressure; and fluidconduit 40 in fluid communication with fluid pressurizer 20 and fluidpressure intensifier 30.

Fluid source 10 may be located on vessel 2 but does not have to be. In apreferred embodiment, fluid source 10 is located distally from seabed100 such as near or at the water surface. Fluid 5 may be a controlfluid, a tree chemical fluid, or the like, or a combination thereof.

Fluid pressurizer 20 is adapted to provide a pressure substantiallylower than the delivery pressure required for injection of fluid 5 tosubsea device 110. Fluid pressurizer 20 may be located proximate thesurface or subsea distally from fluid pressure intensifier 30 and may bepart of fluid source 10, i.e. integrated with fluid source 10, orotherwise in fluid communication with fluid source 10 such as via fluidconduit 11.

Fluid pressurizer 20 is in fluid communication with fluid pressureintensifier 30, which is located proximate seabed 100, such as via fluidconduit 40. In preferred embodiments, fluid pressure intensifier 30 maybe located on seabed 100 or near seabed 110 such as on an ROV (not shownin the figures). Fluid pressurizer intensifier 30 is adapted to providefluid 5 to one or more subsea devices, e.g. subsea device 110, at higherfluid pressure than fluid pressurizer 20 provides. In an embodiment,fluid pressure intensifier 30 is adapted to provide a pressuresubstantially higher than 10,000 PSI and, more preferably, in the rangeof around 15,000 to around 20,000 psi.

In certain embodiments, fluid pressure intensifier 30 comprises aplurality of fluid pressure intensifiers 30 connected in series,parallel, or a combination thereof. One or more fluid pressureintensifiers 30 may utilize proportional hydraulic valves.

In a preferred embodiment, fluid conduit 40 is an umbilical which mayfurther comprise one or more fluid conduits 42, electrical powerconduits 43, data conduits 44, or a combination thereof.

System 1 may further comprise surface control panel 4 operatively incommunication with fluid pressurizer 20, fluid pressure intensifier 30,or both.

In an alternative embodiment, system 1 is adapted to provide aninstallation workover control system and comprises fluid source 10located distally from seabed 100 and adapted to provide fluid 5 suitablefor use with a subsea installation workover function; fluid pressurizer20 in fluid communication with fluid source 10, fluid pressurizer 20adapted to pressurize fluid 5 to a first pressure; fluid pressureintensifier 30 located at a surface location, fluid pressure intensifier30 further adapted to receive fluid 5 at a first fluid pressure andoutput fluid 5 at a fluid pressure higher than the first fluid pressure;and fluid conduit 40 in fluid communication with fluid pressurizer 20and fluid pressure intensifier 30.

Fluid pressure intensifier 30 may be further adapted to be drivenhydraulically from the surface.

In the operation of an exemplary embodiment, fluid under pressure may beprovided for subsea use such as with a subsea installation workovercontrol system by pumping fluid 5 at a first fluid pressure from a firstlocation to fluid pressure intensifier 20 located subsea; increasing thefluid pressure to a higher pressure at the subsea fluid pressureintensifier 20; and providing the increased pressure fluid 5 for usesubsea.

In an embodiment, fluid 5 is pumped at a first fluid pressure from apump located at a surface location or a pump located subsea, e.g. fluidpressurizer 20, but not located proximate fluid pressure intensifier 30.

The foregoing disclosure and description of the inventions areillustrative and explanatory. Various changes in the size, shape, andmaterials, as well as in the details of the illustrative constructionand/or a illustrative method may be made without departing from thespirit of the invention.

1. A method of providing fluid under pressure for subsea use,comprising: a. pumping a fluid at a first fluid pressure from a firstlocation to a fluid pressure intensifier located subsea; b. increasingthe first fluid pressure to a higher fluid pressure at the fluidpressure intensifier located subsea; and c. providing the higher fluidpressure fluid to a device for use subsea.
 2. The method of claim 1,wherein the fluid is pumped at a first fluid pressure from at least oneof (i) a pump located at a surface location or (ii) a pump locatedsubsea but not located proximate the fluid pressure intensifier.
 3. Themethod of claim 1, wherein: a. the device is a component of a subseainstallation workover control system; and b. the fluid is adapted to beused with the device for a subsea installation workover control systemfunction.
 4. A system for providing fluid under pressure for subsea use,comprising: a. a fluid source located distally from a seabed and adaptedto provide a fluid suitable for use with a subsea device; b. a fluidpressurizer in fluid communication with the fluid source, the fluidpressurizer adapted to pressurize the fluid to a first pressure; c. afluid pressure intensifier located subsea, the fluid pressureintensifier further adapted to receive the fluid at the first fluidpressure and output the fluid at a fluid pressure higher than the firstfluid pressure; and d. a fluid conduit in fluid communication in betweenthe fluid pressurizer and the fluid pressure intensifier.
 5. The systemof claim 4, wherein the subsea device is adapted to provide apredetermined installation workover function.
 6. The system of claim 4,wherein the fluid is at least one of (i) a control fluid or (ii) a treechemical fluid.
 7. The system of claim 4, wherein the fluid pressurizeris adapted to provide fluid at a fluid pressure substantially lower thanthe delivery pressure required for injection of fluid to a subseadevice.
 8. The system of claim 4, wherein the fluid pressurizer islocated at least (i) proximate the surface or (ii) subsea distally fromthe fluid pressure intensifier.
 9. The system of claim 4, wherein thefluid pressure intensifier is adapted to provide a pressuresubstantially higher than 10,000 PSI.
 10. The system of claim 4, furthercomprising a surface control panel operatively in communication with atleast one of (i) the fluid pressurizer or (ii) the fluid pressureintensifier.
 11. The system of claim 4, wherein the fluid conduit is anumbilical.
 12. The system of claim 11, wherein the umbilical furthercomprises at least one of (i) a fluid conduit, (ii) an electrical powerconduit, and (iii) a data conduit.
 13. The system of claim 4 the fluidpressure intensifier comprises a plurality of fluid pressureintensifiers.
 14. The system of claim 13, wherein a first of theplurality of fluid pressure intensifiers is fluidly connected to atleast one other of the plurality of fluid pressure intensifiers.
 15. Thesystem of claim 13, wherein the plurality of fluid pressure intensifiersare fluidly interconnected in at least one of a series or parallel fluidconnection.
 16. A system for providing an installation workover controlsystem, comprising: a. a fluid source located distally from a seabed andadapted to provide a fluid suitable for use with a subsea installationworkover function; b. a fluid pressurizer in fluid communication withthe fluid source, the fluid pressurizer adapted to pressurize the fluidto a first pressure; c. a fluid pressure intensifier located at asurface location, the fluid pressure intensifier further adapted toreceive fluid at a first fluid pressure and output the fluid at a fluidpressure higher than the first fluid pressure; and d. a fluid conduit influid communication with the fluid pressurizer and the fluid pressureintensifier.
 17. The system of claim 16, wherein the fluid pressureintensifier is adapted to be driven hydraulically from the surface.